• NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    Hundreds of Questions Highly Detailed Reporting Expert Explanations TAKE A FREE GMAT QUIZ
  • 7 CATs FREE!
    If you earn 100 Forum Points

    Engage in the Beat The GMAT forums to earn
    100 points for $49 worth of Veritas practice GMATs FREE

    Veritas Prep
    VERITAS PRACTICE GMAT EXAMS
    Earn 10 Points Per Post
    Earn 10 Points Per Thanks
    Earn 10 Points Per Upvote
    REDEEM NOW

Absolute value

This topic has 3 expert replies and 1 member reply

Absolute value

Post

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Difficult



If $$\left|X^2\ -\ 6\right|\ =\ X$$ , which of the following could be the value of x?

A) -2
B) 0
C) 1
D) 3
E) 5

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post
harsh8686 wrote:
If $$\left|X^2\ -\ 6\right|\ =\ X$$ , which of the following could be the value of x?

A) -2
B) 0
C) 1
D) 3
E) 5
A quick approach is to simply test the answer choices

A) -2 No good. The absolute value of something cannot be negative
B) 0 Plug in to get |0² - 6| = 0. Doesn't work.
C) 1 Plug in to get |1² - 6| = 1. Doesn't work.
D) 3 Plug in to get |3² - 6| = 3. WORKS!!!

Answer: D

Cheers,
Brent

_________________
Brent Hanneson – Creator of GMATPrepNow.com
Use our video course along with Beat The GMAT's free 60-Day Study Guide

Sign up for our free Question of the Day emails
And check out all of our free resources

  • +1 Upvote Post
  • Quote
  • Flag
GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!

GMAT/MBA Expert

Post
harsh8686 wrote:
If $$\left|X^2\ -\ 6\right|\ =\ X$$ , which of the following could be the value of x?

A) -2
B) 0
C) 1
D) 3
E) 5
Alternate approach:

Since an absolute value cannot be negative -- implying that the right side of the equation must be NONNEGATIVE -- we know that x≥0.
If x²-6=x, we get:
x²-x-6=0
(x-3)(x+2) = 0
Only the factor in green implies a nonnegative option for x:
x-3=0
x=3.

The correct answer is D.

_________________
Mitch Hunt
Private Tutor for the GMAT and GRE
GMATGuruNY@gmail.com

If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.

Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.
Student Review #1
Student Review #2
Student Review #3

  • +1 Upvote Post
  • Quote
  • Flag
Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.
Newbie | Next Rank: 10 Posts Default Avatar
Joined
14 Nov 2017
Posted:
6 messages
Post
harsh8686 wrote:
If $$\left|X^2\ -\ 6\right|\ =\ X$$ , which of the following could be the value of x?

A) -2
B) 0
C) 1
D) 3
E) 5
Absolute values can be time-consuming to deal with, because you have to split into two different cases and work them out. In this situation, the approach Brent mentioned, testing the answer choices, will be the fastest approach.

  • +1 Upvote Post
  • Quote
  • Flag
Post
harsh8686 wrote:
If $$\left|X^2\ -\ 6\right|\ =\ X$$ , which of the following could be the value of x?

A) -2
B) 0
C) 1
D) 3
E) 5
Looking at the answer choices we see that when x = 3, we have:

|9 - 6| = 3

3 = 3

Answer: D

_________________
Scott Woodbury-Stewart Founder and CEO

  • +1 Upvote Post
  • Quote
  • Flag
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep

Top First Responders*

1 fskilnik@GMATH 55 first replies
2 GMATGuruNY 52 first replies
3 Brent@GMATPrepNow 51 first replies
4 Jay@ManhattanReview 39 first replies
5 Rich.C@EMPOWERgma... 23 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

198 posts
2 image description fskilnik@GMATH

GMATH Teacher

154 posts
3 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

97 posts
4 image description Max@Math Revolution

Math Revolution

89 posts
5 image description GMATGuruNY

The Princeton Review Teacher

76 posts
See More Top Beat The GMAT Experts